Telegraphone



Nov. 11,1947. RMSOMERS 2,430,538

TELEGRA-PHONE Filed June 14, 1944 4 Sheets- Sheet r1 Rich-ava Mmers Nov. ll, 1947. R. M. soMERs TELEGRAPHONE Filed June 14, 1944 4 Sheets-Sheet 2 1 l l l l l l l l l l v W Noir. ll, 1947. R. soMERs TELEGRAPHONE Filed June 14, 1944 4 Sheets-Sheet 3 Richard M', Somers Nov. 1&1, 1947. R, M SOMERS 2,430,538

TELEGRAPHONE Filed June 14. 1944 4 Sheets-Sheet 4 Suncntor Rl'CFza-rcl M Samers Patented Nov. 11, 1947 TELEGRAPHONE Richard M. Somers, West Orange, N. J., asslgnor Thomas A.

dison, Incorporated, West Orange, N. J., a corporation of New Jersey Application June 14, 1944, Serial No. 540,259

11 claims. (c1. er1- 2.1)

This invention relates to telegraphones and more particularly to improvements in the construction, operation and control of telegraphones.

The subject matter of this application is disclosed in the joint application of the applicant and Roscoe C. Van Camp, Serial No. 520,508,

4iled January 31, 1944, and entitled Telegraphone,

and issued June 10, 1947, as Patent No. 2,422,143, and many features of the disclosure not claimed herein are claimed in the prior joint application. I

While not hunted thereto, the invention has particular application to recording and reproducing telegraphones which operate a multiple times along a magnetic medium in transverselyspaced lanes of that medium, such telegraphones being known as the multiple-lane type. By way of preferred illustration, the invention is shown in connection with a telegraphone having a removable magazine carryinga recording medium in the form of a magnetic tape.

It is an object of my invention to provide improved drive and control mechanisms for telegraphones and, more especially, to provide a positively-acting means for reversing automatically the magnetic recording medium, or tape, at the end of travel thereof in each direction.

Other objects of my invention are to provide a control system for reversing a tape-driving mechanism which will effect a reversal only in response to a complete reciprocation of a control device thereof, to provide means `for positively reciprocating such device at the end of travel of the tape in each direction, to provide a control system having two such control devices for starting the drive mechanism in its respective directions, to provide a, control system wherein the respective control devices are rendered ineffective in the system upon initial operation thereof following the operation of the other, and to provide such control system wherein the respective control devices are rendered ineffective alternately, each by the operation of the other.

Further objects are to provide a reversing mechanism which is first conditioned for operation and thereafter operated in response to unidirectional movement of a predetermined portion of the tape, and to provide a thickened or corrugated portion of the tape for so operating the mechanism which has a length adapted to assure positive operation of the mechanism at the end of travel of the tape in each direction.

It is a further object to provide a reversing switch for the tape-driving mechanism and sepi arate control Switches for starting the drive 2 mechanism in its respective directions, which control switches are rendered effective alternately in the system by the reversing switch.

It is another object to provide improved means for reversing the tape and selectively conditioning the machine for operation on the respective lanes of the tape.

Still other and allied objectsandfeatures ofl my invention will appear from the following description and the appended claims.

In the description of my invention reference is had to the accompanying drawings. of which:

Figure 1 is a perspective view of a telegraphone embodying my invention:

Figure 2 is a front elevational view of the removable magazine of that telegraphone;

Figure 3 is a top pian view, witha cover portion removed, of the abovementioned magazine;

Figure 4 is a fractional sectional view taken `substantially on the line 4 4 of Figure 3;

Figure 5 is a detailed fractional view illustrating the operation of the selector control switches of the magazine by the magnetic tape;

Figure 6 is a fractional sectional view taken substantially on the line 6-6 of Figure 3;

Figure '7 shows utop and bottom views to reduced scale of cooperating parts of ratchet drive transmissions for the supply and take-up reels of the magnetic tape;

Figure 8 is a top plan view of the cabinet sec-- ping-relay selector mechanism provided in the lower cabinet section;

Figure 12 is a View, partly broken away, taken substantially on, the line |2--I2 of Figure 13;

Figure 13 is an axially sectional view of the stepping-relay mechanism, taken substantially on the line i3-I3 of Figure l1;

Figure 14 is a detailed sectional View taken substantially on the line i4-I4 of Figure 10;

Figure 15 is a fractional sectional view taken substantially on the line ii-iii of Figure 8;

Figure 16 is a fractional sectional view taken substantially on the line IB-IE of Figure 8; and Figure 17 is a diagrammaticview oi circuits and mechanism according to my invention.

As is shown in Figure 1, the present telegraphone comprises a substantially rectangular cabinet I having a lower or main section 2 and l machine, and may be removed and replaced by only one drive coupling is required between the,

main cabinet section and the magazine. Reference being had to the top plan view of the magazine shown in Figure 3, the drive mechanism will be seen to comprise two reels and 6 for a magnetic tape 1. These reels are positioned in the front portion of the magazine respectively at the left and right corners thereof, in which positions they are journalled on studs 8 held by screws 9 to the bottom wall of the magazine as indicated in Figure 6. It will be understood that these reels serve alternately as supply and take-up reels, depending upon the direction of travel of the tape. For instance, in the direction of travel of the tape indicated by the arrows I Il in Figure 3, the lefthand reel 5 serves as a supply reel and the righthand reel 6 as a take-up reel. Between these reels, as from reel 5 to reel 6, the tape passes approximately 180 around an idler pulley II, then leftwardly and approximately 180 around a drive pulley I2, then rightwardly through a tone head box I3 to a second drive pulley I4, next approximately 180 around this drive pulley and leftwardly to a second idler pulley I5, and thereafter'approximately 180 around this idler pulley to the take-up reel 6. The drive pulleys I2 and I4 serve alternately, depending upon the direction of travel of the tape, to pull the tape at constant speed through the tone head box, and in order that they may drive the tape without slippage the peripheries thereof are covered with a layer I6 of a frictional material, such as of rubber, as shown in Figure 6.

In the direction of travel of the tape indicated 'by the arrows I0, the operation of the drive mechanism is as follows: the take-up reel 6 is overdriven with frictional slip so that the tape 1 ahead of the drive pulley I4 will be held taut against the drive pulley I4. This pressure of the tape against the drive pulley I4 serves to produce a frictional driving connection of the pulley to the tape so that the pulley pulls the tape rightwardly through the tone head box I3. concurrently the supply reel 5 exerts a frictional drag on the tape and holds the tape under tension as it is pulled through the box. y

For operating the drive mechanism in the magazine there is an electric motor I1 provided in the lower cabinet section 2. This motor is coupled through a gear reduction transmission I8 to an upstanding shaft I9 as shown in Figures 10 and 16. Splined to the upper end of the shaft is a clutch member 20. This member has a set of 'diametrically disposed vertical pins 2| adapted to engage a corresponding coupling member 22 on the magazine to effect a drive connection of the motor to the drive pulley I2 when the magazine is in mounted position, the manner in which this 4 coupling is made being hereinafter described in detail.

The coupling member 22 has 'an upstanding shaft 23 integral therewith which is journalled in a bearing 24 held by screws 25 to the bottom wall of the magazine. The drive pulley I2 is secured to theshaft 23 by a set screw 26 and seats onto, and surrounds, the bearing 24 as shown in Figure 6.

The means for taking power from the pulley I2 to operate the drive mechanism in the magazine comprises ado'ubly-grooved pulley 21 formed integrally with the drive pulley I2, a similar doubly-grooved pulley 28 formed integrally with the drive pulley I4 (the pulley I4 being journalled on a. stud bolt 3| held to the bottom plate of the magazine as shown in Figures 2 and 3), and two similar doubly-grooved pulleys 29 and 30 journalled on the stud bolts 8 below the reels 5 and 8 as indicated in Figures 3 and 6. These four pulleys are drivingly interconnected by a pair of cords or belts 32 which run over tensioning idler pulleys 33 provided respectively between the pulleys 21 and 29 at the left side of the magazine and between the pulleys 28 and 30 at the right side of the magazine, these idler -pulleys being journalled on brackets 34 which are adjustably secured to the bottom wall of the magazine.

The pulleys 29 and 30 are coupled to the respective reels 5 and 6 by means of frictional and ratchet drive transmissions such as are shown in Figures 6 and 7, these transmissions being identical except for the ratchet drives being oppositely directed as indicated in Figure 7. The transmission between the pulley 29 and reel 5, for example, comprises a pair of upwardly-bowed leaf springs 35 held to the top face of the pulley 29 by screws 36. These springs engage the lower face of a ratchet wheel 3l. This ratchet wheel is journalled on the upper portion of the stud bolt 8 against the hub of the pulley 29, and has four v radially-extending slots 38 with which the tips of the springs 35 may engage to eiect a one-Way coupling between the pulley 29 and ratchet wheel. The hub 5a of the reel 5 is journalled to the hub 31a of the ratchet Wheel and is pressed yieldably against the top face of the ratchet wheel by downward pressure of a compression spring 40 acting against a washer 39 loosely surrounding the hub 31a, the compression spring being held in position by a nut 4I that is threaded onto the top portion of the hub 31a. However, interposed between the hub 5a of the reel and the top and bottom faces of the ratchet wheel 3l and washer 39 respectively are friction pads 42 made for example of felt. The yieldable clamping of these pads against the hub of the reel 5 permits frictional slip between the ratchet wheel and the reel.

The coupling between the pulley 30 and reel 6 is identical with the coupling between the pulley 29 and reel 5 as just described except that there is here provided a pair of springs 43, corresponding to the springs 35, which are oppositely directed from the springs 35 for coaction with a ratchet Wheel 44 similar to the wheel 31 as shown in Figure '7. As is illustrated, the one-way ratchet coupling between the pulley 29 and thereel 5 is effective when the pulley moves in a counterclockwise direction and that between the pulley 30 and reel 6 is effective when this pulley moves in a clockwise direction. Thus, when the tape is driven in the directions of the arrows I0 appearing in Figure 3, the coupling to the take-up reel is engaged but that to the supply reel is disengaged.

i All of the pulleys 21,v 28, 29 and 30 have equal diameters so that they will be driven at the same rotational speed by the motor I1. The diameters of the coils of tape on the reels and 8 are however always greater than the diameter of the drive pulleys I2 and I4. Accordingly, when the tape is vdriven in the direction of the arrows Ill, the reel 6 tends to be driven at the same rotational speed asthe drive pulley I4, but thel greater diameter of the coil of tape on the reel 8 causes this reel to tend to take up the tape at a faster rate than it is supplied by the drive pulley. 'I'he reel 8 thus holds the tape taut against the drive pulley I4and the drive pulley becomes controlling because the frictional coupling of it to the tape overpowers the'frictional coupling between the reel 5 and its corresponding drive pulley 30, withrthe result that the take-up reel is constantly overdriven with frictional slip as above-mentioned. At the same time the ratchet coupling to the supply reel 5 is moved in ineffective direction and no force is exerted on the reel to unwind the tape; rather, the friction in the mounting of the reel causes it to exert a dragon thev is disengageable to permit withdrawal of the magazine from the cabinet and is controlled to reengage automatically when the magazine is remounted. For these purposes, as is shown in Figures 8 and 16, the clutch member 20 is biased upwardly by a spring 45 into position to engage the coupling member 22 of the magazine, and a control lever 46 is connected to the clutch member for disengaging the clutch member as required. The control lever is DlYOted to a bracket 41 on the top side 2a of the lower cabinet section 2, near the front left corner thereof, and has two rearwardly-extending arms 46a lying at diametrically opposite sides of the clutch member. These arms have pins 48 which engage a peripheral groove 49 in the clutch member so as to couple the control member to the clutch. Under pressure of the spring 45 the control lever is normally held in a slightly upwardly inclined position as r shown in Figure 16.

'Overlying the central and major portion of the top side 2a of the lower cabinet section 2 is a latch member 50 for the magazine. This latch member comprises a fiat plate portion pivoted at 5| to the rearward portion of the cabinet, and a front portion projecting ahead of the front panel of the cabinet which is bent upwardly to form a catch 52 and then forwardly and gradually downwardly to form a cam 53. The latch mem- .ber is biased upwardly by a leaf spring 54 mounted on the top side of the lower cabinet section 2, and the upper position of the latch member is dened by a stop pin 55 as shown in Figures 8 and 15. At the left side of the latch member there is a tab 56 overlying the clutch control member 46 and at the right side of the latch member there is another tab 51 overlying a Dushof the machine.

move the latch member downwardly. As the latch member is so moved the tab 5B depresses the clutch lever 46 to move the clutch member 2li downwardly out of the path of the magazine, and the tab 51 operates the switch 58 to`oil position so as to assure that the drive motor will be stopped. When the magazine reaches fullymounted position, it slides off the catch 52 and the latch member then is snapped upwardly by its biasing spring to latch the magazine in the/cabinet. 'I'he upward movement oi the latch member frees the clutch lev'er'l to permit reengagement of the clutch member 204 with the corresponding coupling member 22 of the magazine and, simultaneously, the switch 58 is restored to on position so that the drive motor may again be put in operation. (It will be understood that a primary start-stop control for the drive motor is provided, as is hereinafter explained, and that the switch 5B is provided as a precautionary means to assure, among other things hereinafter explained, that the drive motor will be idle during mounting and removal of the magazine into andout of the cabinet.) y clutch member 20 will not ordinarily be aligned with the holes in the coupling member 22 to permitthe clutch member to engage immediately upon the magazine reaching mounted position, this alignment will occur in the first fraction of a revolution of the clutch member and the clutch member will then move to engaged position under the influence of the spring 45.

When a magazine is to be removed from the cabinet the latch member 50 is rst released from the magazine by applying a downward pressure with the hand onto the forwardly-projecting cam 53. This is accomplished automatically as the handle 4 is gripped by the hand for the cam 53 I lies directly below the handle where it will be pressed downwardly by the iingers -as one takes hold of the handle to withdraw the magazine as shown in Figure 1. This downward movement of the latch member causes the clutch to be disengaged and the motor circuit again to be opened,

permitting the magazine to be withdrawn from the cabinet Without danger of any misoperation It will be understood that the latch member need be depressed only during the initial withdrawal ofthe magazine from the cabinet, for as soon as the magazine has been moved out of mounted position the bottom thereof will engage the catch 52 and hold the latch member depressed during the further withdrawal of the magazine. Thus, the magazine is unlatched and removed simply by gripping the handle` 4 and pulling outwardly from the cabinet.

The telegraphone here shown is of the multiple-lane type. 'I'hese telegraphones require a translating means which is conditionable selectively Afor coaction with successive lanes of the tape. Such selective conditioning may be effected by moving a single tone head, by steps, across the tape so that it will operate along successive lanes of the tape. Preferably however there is provided a plurality of offset tone heads, one for each lane of the tape, and the selective condi- `tioning is performed by connecting these tone heads selectively to the audio circuit of the machine. The aforementioned tone head box I3 therefore comprises a plurality of consecutively offset tone heads 60 of which there are typically eight as shown in Figure 1'1. Each of these tone vheads comprises a pair of field coils 5I and respective core pieces 62' placed axially in line with each other at opposite sides of the tape. Thel While the pins 2| of thel 7 construction of these tone heads is conventional and need not be herein further described.

In operation, the tape is driven in,one direction while the audio circuit is connected to one of the tone heads, and when the tape has reached the end of its travel in that direction it is reversed and the audio circuit is connected to the next one of the tone heads. 'I'his procedure is continued ordinarily until each tone head has scanned the tape, whereupon the magazine may be removed for transcription of the recordation and another magazine may be mounted in the cabinet in its place.

The audio circuit may be adapted for recording or reproducing-i. e., to feed electrical oscillations to the tone heads or to receive electrical oscillations from the tone heads-but by way of illustration there is shown an audio circuit primarily adapted for recording purposes only. This audio circuit comprises simply a carbon button microphone 65 together with a suitable operating circuit for the microphone and switch for connecting the microphone selectively to the tone heads. The microphone has a pair of leads 66 connected respectively to the sleeve and ring contacts 61 and 68 of a suitable telephone plug shown diagrammatically in Figure 17 as 10, this plug having also a tip 69 the function of which is hereinafter explained. The plug is adapted for insertion into a telephone jack 10a provided in the front panel of the lower cabinet section 2 and marked Input as shown in Figure l. The jack has sleeve, ring and tip contacts 61a, 68a and 69a respectively, and additionally includes a normally open switch 1I comprising a pair of contact springs of which one is coupled through an insulating block 12 to the tip 69a so that the switch will be closed whenever the plug 10 is inserted into the jack. The sleeve contact 61a of` the jack is grounded at 13-1, e., connected to the frame of the machinewhile the ring contact 68a of the sleeve isvconnected through the primary winding 15a of an audio transformer 15 to an adjustable tap 18 of a volume control or rheostat 11.

to one side of a battery 18 by way of the aforementioned switch 58, a second switch 19 hereinafter particularly described, and the switch 1l just mentioned above. The other side of the battery 18 is connected to ground as shown. Thus,

One end of this rheostat is connected to ground but the other end is connected whenever the switches 58 and 19 are closedl which the switch 58 is when a, magazine is mounted in the cabinet and the switch 19 is when the selector mechanism of the machine is in correct operating condition as will hereinafter appearbattery potential is available to the microphone upon the plug being inserted into the jack. However, in the microphone circuit 66 there is a pair of make-and-break contacts 80 of anormally open hand switch 8l which is provided for starting and stopping the machine as during dictation. Accordingly, potential is supplied to the microphone to render it operative only when this hand switch is closed to start the machine.

In the lower cabinet section 2 there is a selector switch 82 for selectively connecting the microphone to the respective tone heads 60. This switch comprises a set of terminals 83 of which there is one for each tone head and a rst idle terminal 83a. Associated with this set of terminals 83 is a movable contact means 84 connected by a shielded lead 85 to one side of the secondary 15b of the audio transformer 15, the other side of this secondary being connected to ground.

The terminals 83 of the selector switch, except for the idle terminal 83a, are connected respectively to a set 86 of contact springs included in a bank 81, the springs of this bank being mounted in an insulating block 88 that is supported at the top of the lower cabinet section 2 as shown in Figure 8. Additionally, corresponding to the idle terminal 83a, there is another one of such contact springs 86a'which is however permanently connected to. ground. These contact springs bow upwardly above the block 88 and are exposed to the magazine chamber by way of an opening 50a provided in the latch member 50. At the bottom of the magazine there is mounted a terminal bank 89 including a set of terminals 90 and 90a corresponding to the contact springs 86 and 86a of the bank 81, these terminals being mounted in an insulating block 9| as indicated in Figure 3. These terminals of the magazine slidably engage the respective contact springs 86 as the magazine is slid into the cabinet. The i'lrst of the terminal set 90 on the magazine, designated as 90a in Figure 17 and corresponding to the grounded contact spring 86a of the bank 81, is itself grounded to the frame of the magazine and connected by a lead 92 to one side of each of the tone heads; the other eight terminals of the set 90 are however connected by a. shielded cable 93 to the other sides of the respective tone heads. From the foregoing description it will be apparent that voice currents from the microphone 65 will be fed to one or another of the tone heads 60, depending upon the setting of the selector switch 82, by way of the transformer 15, shielded lead 85, the movable contact means 84 and associated terminal 83 of the selector switch, the respective contact spring 86 and terminal 90 of the banks 81 and 89 betweenl the lower cabinet section and the magazine, and the cable 93.

The reversing of the tape-driving mechanism is preferably carried out by reversing the direction of rotation of the motor I1, and to this end there is provided a motor of the shunt type depending for its direction of rotation upon the re1- ative polarity of its shunt field I1a and armature I1b. This motor is adapted for operation by the battery 18, which may typically have a potential of the order of 24 volts. Current supply to the motor is controlled by a start-and-stop relay 95 for the machine having a eld coil 95a one side of which is connected .by way of the aforementioned switches 58, 19 and 1I (see Figure 17) to the battery 18, and the other side of which is connected to ground by way of the tip contacts of the jack and plug 10a and 10, a pair of makeand-break contacts 80a included in the startstop hand switch 8l and the sleeve contacts of the plug and jack to the ground 13. The shunt field I1a4 has a direct connection to the battery by way of a lead 91, the contacts of the relay 95 and a lead 98, but the current supply to the armature is takerifrom the lead 91 through a reversing switch comprising a section of the selector switch 82. The reversing switch comprises a series of pairs of terminals 99 and a pair of respectively cooperating movable Contact means |00. The first pair 99a of the terminals 99 is idle and represents stop terminals for the motor, but the remaining pairs, of which there is one for each tone head 60, are interconnected in crisscross relationship. The last of these interconnected pairs is connected respectively to the lead 91 and to ground, and the movable contact means |00 are connected across the armature |1b. These movable contact means |00 are meaccusa chanically connected to the aforementioned con- I tact 04 to move in unison therewith asis hereinafter described. Thus. when the movable contacts of the selector .switch are advanced from one position to the next. not only is the micro- .phone 05 connected to a next succeeding one of shown in Figures 10, 11, 12 and 13. The switch comprises a shaft extending forwardly through the front panel of the lower cabinet section 2 and passing through a pair of downwardlyextending legs |02 of a U-bracket |03 held by screws |04 to the top plate 2a of the lower cabinet section. Secured to the shaft |0| by a screw |05 (see Figure 13) is an armature |03 for the switch having a shouldered hub |06a that is journalled in the legs |02 of the bracket |03. Onto this hub there is clamped a small insulating disk |01, the clamping being done by a nut |08 which threads onto the hub and presses the disk against a shoulder portion of the hub. Riveted to this disk are three pairs of contact arms, spaced 120 apart, of which one pair represents the aforementioned movable contact means 84 and the other pairs represent the aforementioned movable pair of contact means |00 of the selector switch as is hereinafter more fully explained. At the front and back of the'armature |06 there are centrally apertured insulating disks and l||2 which are secured to the depending lugs of the bracket |03 and held concentric to the shaft |0|, the front disk being held for example to the bracket by screws ||3 as indicated in Figure 13. This front disk carries twenty-sevenequallyspacedv contact terminals of which one continuous set of nine represent the abovementioned terminals 83 of the selector switch, and the remaining continuous set of eighteen represent the terminals 39 of the reversing switch section of the selector switch. Riveted to the other stationary disk ||2 are three arcuate contact .members ||4, and ||6 which are equally spaced and each approximately 120 long. The contact member 4 is angularly aligned with the terminal set 83 and the two contact members ||5 and H8 are angularly aligned with the terminal set 99'. Each pair of the movable contact means 84 and |00 comprises two electrically interconnected blades that are spaced apart axially along the shaft |0 as shown in Figures 10 and 13. One of these bladesslidably engages continuously one of the arcuate contact members ||4, ||5 or ||6 and the other blade slidably engages one of the terminals 84 or 99. It will be understood that the shielded lead 85 will have direct permanent connection to the arcuate contact member ||4 and that the leads from the motor arma-ture |1b will be connected respectively to the arcuate contact members ||5 and ||8. It will moreover be understood that the last eight of the set of terminals 83 are connected to the respective contact springs 86 as hereinbefore explained, and that one group oi alternate ones of the lastsixteen of the terminal set 99 will be interconnected to each other and be 'connected to ground and that the 10 other group of alternate ones of the last sixteen otthisoet "willbelikewise interconnectedto each other and further connected to the current supply lead l1. Accordingly, it will be observed that withvcontinuous step-by-step advance of the amature |00 in onedirection the selector switch is moved recurrently through its successive positions with the movable contact means 84 and |00 always advancing from leftsto right at they appear in Figure 17 and with each succeeding one of the respective movable contact means 34 and |00 taking on the function of the one just ahead of it after each nine intervals of advance of the armature.

For successively advancing the armature |08 of the selector switch at the endof travel of the tape in each direction, I provide a stepping mechanism which together `with the selector switch 82 may be termed a stepping relay. This stepping mechanism comprises a ratchet |20 operated by a solenoid |2| as shown in Figures 11 and 13, The ratchet comprises a ratchet wheel |22 positioned behind the bracket |03 and made integral with the aforementioned hub'l00a. Pivoted at |23 to; the bracket |03 is a rock lever |24 and pivoted at |25 to one end portion of this rock lever is a feed pawll |28 which is urged by a tension spring |21 into engagement with the ratchet wheel. Coupled "v a link |28 to the other end of the rock lever is the armature |23 of the solenoid 2|. type and comprises a coil |30 surrounded by a rectangular iron frame |3| and provided with a core piece |32, all as is indicated in Figure 11.

When the solenoid is not energized, the rock lever |24 is held in an advanced or operated position by a tension spring |33 connected between the lever and the plate 2a, which position is clenecl by the abutment of the lever against an adjustable screw |33a in a turned-over lug of the bracket |03. When the solenoid |2| is energized, the rocklever is turned from its advanced position against the @force of the spring '|33 but in so turning it does not impart any movement to the armature |06 of the selector switch, the effect of this turning being only tocock the ratchet |20 by withdrawing the feed pawl |26 from one tooth to the next of the ratchet wheel |22. Upon interrupting the current supplied to the solenoid, `however, the rock lever |24 is propelled forwardly by the spring |33 to advance the selector switch from one position to the next.

In accordance with my invention, the solenoid |2| is controlled so that it will be momentarily energized once at the end of travel of the tape in each direction. The means for so controlling the solenoid comprises a pair of selector control switches |34 and |35 respectively comprising semistationary contact arms 34a and |35a and movable contact arms |34b and |35b, the arms of each switch being biased to open positions. These switches are positioned'in the magazine between the idler pulleys and l5 of the magnetic tape drive mechanism, the switches being held insulatedly in cantilever fashion in a stack |36 which is bracketed to the bottom plate of the magazine. The outer sides of the movable contact arms |34b and |351) are faced by insulating strips |31. These strips lie adjacent to the idler pulleys and I5, with the magnetic tape passing between the 'strips and the pulleys. On the magnetic tape 1, near each end thereof, there is a thickened strip portion 1a. As this strip portion rides over one or the other of the idler pulleys or I5, it presses ythe adjacent strip |31 inwardly This solenoid is preferably of the ironclad Reference being had to Figure 17, it will be seen that the two semistationary contact arms |34a and |35a oi' the switches |34 and |35 are each connected by a common lead |31 to one side of the solenoid |2|, the other side of the solenoid being grounded as shown. This lead connection is made from the magazine to the lower cabinet section 2 through contact terminals and contact springs |38 and |33 comprised in the aforementioned switch contact banks 88 and 81. The movable contact arms of the switches |34 and |35 are connected by leads |40 and |4I, respectively by way of terminals and contact springs |42|43 and |44|45 of the banks 88 and 81, to the respective movable contact means of the reversing section of the selector switch.

In the positions occupied in Figure 17 by the movable contact means |00 of the selector switch, potential from the battery 18 is supplied to the lead |4| running to the switch |35 provided of.

course the start-stop relay 35 is closed. For the direction of travel of the tape indicated by the arrows I0 in Figure 3, the switch |35 will be closed by the corrugated tape portion 1a running over the idler pulley I as the tape nears the end of its travel. When the switch is closed by the corrugated tape portion 1a, the solenoid |2| withdraws the pawl |26 from one tooth to the next succeeding one of the ratchet wheel |22;

and then when the corrugated tape portion 1a has moved past the switch and the switch reopens to deenergize the solenoid, the relay is advanced one interval by the spring |33 acting through the pawl and ratchet wheel. In the initial reverse travel of the tape following the advance of the selector switch, the tape section 1a will again ride over the idler pulley to close and open the switch |35, but the tape will continue to be driven in its reverse direction since it is a feature of my invention that upon operation of either switch |35 or |34 the same is disabled from further controlling the machine until theother of the two switches is operated. This is accomplished by alternately connecting the contact arms |34b and |35b of switches |34 and |35 to ground and to the battery 18 as the selector switch is advanced from one position to the next. For example, in the operation of the selector switch at the end of travel of the tape in the direction of the arrows of Figure 3, the

lower contact |00 is advanced one step from the position it occupies in Figure 17 to connect switch |35 to ground and the upper contact |00 is advanced one such step to connect switch |34 to the battery 18,. When the tape nears the 'end of its travel in its reversed direction, the switch |34 will be next momentarily closed to cause the selector switch to be advanced another position. This reverses the direction of travel of the tape and causes switch |34 to be now grounded and switch |35 to be connected to the battery 18 so that the tape will continue to be driven throughout the length of its travel again in the direction of the arrows 0 of Figure 3. Upon continued operation of the machine this process will continue with the selector switch advancing successively at the end of travel of the tape in each direction. the last line of the tape, however, the selector switch is advanced to place the movable contact At the completion of recordation of 12 means 84 and |00 in contact with the idle terminals 83a and 88a, whereupon the operation of the machine is stopped.

Due to the inertia of the plunger |28 and of the mechanism coupled thereto, there is unavoidably some delay in the response oi' the plunger to current energization of the solenoid coil |30. As a result, because of the high speed oi travel of the tape 1, a single corrugationoi the tape does not hold the switches |34 or |35 closed suillciently long to assure positively that the pawl |28 will be retracted and the stepping mechanism be then operated when the switches are next opened. However, according to my invention the portions 1a are made of such length-that, taking into account the speed of the tape, the switch |34 or |35 will be held closed for a suillclent period to assure full retraction of the pawl and consequent operation of the stepping mechanism when the switch is reopened.

It will be observed that the switches |34 and |35 are rendered effective alternately in the machine by the reversing section of the selector switch 82; moreover, it will be noted that by not advancing the selector switch until the switch |34 or |35 last closed is restored to open position, and by then transferring the control function from that one of the switches |34 or |35 to the other simultaneously with the operation of the selector switch, I obtain a very positive and dependable operation of the selector mechanism at the end oi travel of the tape in each direction.

Upon sliding the magazine out of and into the cabinet the bottom wall thereof may slidably engage the contact springs of the bank 81 and short them with one another. This produces no effect however because in positions of the magazine wherein this snorting occurs, the switch 58 is in oi position and the whole telegraphone system is out of operation. I

Just behind the front panel of the lower cabinet section 2 there is a dial |46 having a hub |41 secured by a set screw |48 to the shaft |0|. This dial has numbers thereon one of which is rendered visible through a window |49 of the front panel in each position of the selector switch. The number exposed indicates the position occupied by the selector switch or, in other words, the lane of the tape on .which the machine is operating. For example, the dial has the number 0 at the window |49 when the movable contact means 84 and |00 of the selector switch are in open positionsi. e., in contact with the idle terminals 83a and 99a. In clockwise direction from the number 0" are numbers running consecutively from l to 8. When the selector switch is in the first of its closed positions, the position which it occupies in Figure 17, the number 1 on the dial appears at the window |49, and for the next higher positions of the selector switch a corresponding` number on the dial will appear at the window. Since the selector switch is advanced through the range of its positions for each advance of the armature |06 of the switch, this succession of numbers from 0 to 8 is repeated within each 120 angular interval on the dial, there being accordingly three such sets of numbers as shown in Figure 9.

In the usual and customary operation of the machine the operator will begin recordation on the first lane of the tape, i. e., with the selector switch in position 1. Sho d an operator have recorded on only some of the lanes of the tape when he removes the magazine for transcription of the recordation, the selector switch will be the shaft joint invention with 'Roscoe C. Van Camp abovementioned to have this knob normally locked, and to require that it be depressed before it is operable to advance the selector switch. An advantage in this mode of enforced operation of the knob arises by the provision of three equallyspaced and radially-projecting fins on the knob, and of a stop pin |52 on the front panel for cooperation with these ns as indicated in Figures 1 and 10. In the outward position of the knob the fins |5| clear the stop pin |52 to permit the selectorswitch to be advanced automatically at the end of travel of thetape in each direction. When the knob is depressed, however, the pin will lie in the path of these fins and will serve, by its abutment against one or another of the fins, to stop the knob in 1" position 0f the selector switch.

In order to facilitate this manual return of the selector switch to 1 position, there is provided Ameans operable automatically to latch the knob in depressed position upon the knob being depressed While in any position of the selector switch other than its 1 position; thev latch is however release'd when the selector switch is restored to 1 position. This latch means comprises a disk member |53 secured to and projecting from thel hub |41 of the knob. This disk member has an inclined peripheral surface |53a provided with three equally-spaced peripheral slots |53?) eX- tending through the member. Pivoted to the front leg of the bracket |03 at |54 is a latch arm |55 as shown in Figures 10 and 14. This latch arm has a nose |55a sufiiciently narrow to pass through the respective slots |5312. Normally, the latch is held against a stop pin |56 by a spring |51 in which position thereof the nose |5511 lies just behind the inclined peripheral surface |53a of the disk Vmember |53. Upon depressing the knob while in an intermediate position the latch arm is cammed over the member |53 .and the knob is thus latched in its depressed position. However, upon the knob being turned to restore the selector switch to 1" position, the nose will come into alignment with one of the slots |531) and the knob will then be snapped outwardly by spring means acting on the shaft |0| as hereinafter described. Thus, to `manually return the-selector switch to l position it is only necessary to first press inwardly on the knob and then only to turn the knob in a counterclockwise direction until it is stopped by the abutment of one ofthe fins I5| against the pin |52.

To permit the vknob |50 to be depressed as above explained, the shaft |0| has a splined connection with the hub |0611, which connection is afforded by providing an axial slot |05a in the hub |06a and having the aforementioned pin |05 disposed within this slotas shown in Figure 13. Bearing against the rearward end of the It is however a feature of my Finire 11. This arm carries across pin |60 at its outer end, and is biased inwardly relative to the feed pawl |28 by a tension spring |6| into a position wherein the pin |60 lies directly behind the feed pawl. This position of the arm is dened by contact of a reduced diameter end portion |0|a of the shaft |0| with the edge of a circular hole |62-provided in an offset portion |60a of the arm |59. When the pin |60 lies behind the feed pawl, the pawl -is locked in engagement with the ratchet wheel |22 and the ratchet wheel is therefore prevented from being advanced by means of the shaft |0|i. e., from being turned clock- `wise as it appears in Figure 11; on the contrary,

the ratchet wheel may be advanced by the feed pawl as above explained. Backward movement of the ratchet wheel is prevented by means of a detent |63 as indicated in Figure 11. Accordingly when the pin |60 lies behind the feed pawl the selector switch is locked against being moved manually by the knob in either direction. On the shaft |0`| just in front of the hole |62 in thearm |59 there is however a conical cam I 64 formed incidental to reducing the diameter of the end portion of the shaft as shown in Figure 13. When the shaft |0| is depressed, this cam |64 engages the edge of the hole |62 and turns the arm |59 so as to move the pin |60 beyond the end of the feed pawl. The feed pawl is then no longer heldin locked engagement with the ratchet' wheel and, accordingly, the selector switch may now be advancedby the knob |50.

In order to insure that the drive mechanism will be at standstill during the manual return oi' the selector switch to 1 position, there is provided means to cause the aforementioned switch 'I9 to be held open while the knob |50 is depressed. This switch comprises a pair of cantilever-mounted contact `arms 19a held, with the aforementioned arm |58, in a stack |65, the stack being held by screws |66 to the back side of the bracket |03 as shown in Figures 11 and 13. The armV |58 is clamped between the contact arms 15a against the back one of these arms but is made of an insulating mate-rial so that it will not form any electrical connection to the arms. The contact armeare biased closed and assume this position when the shaft |0| is moved to outward position by the arm 58. Upon depressing the shaft by the knob |50, however, the arm |58 is moved rearwardly and the switch 19 is thereby opened.

yReference being had to Figure 17, it will be observed that when this switch is open the circuit of the start-stop relay 95 for the machine is held open to prevent operation of the machine.

As a panel light and signal for indicating when the machine is in operative condition, there is provided a lamp |61 which is bracketed to the shaft |0| is a cantilever-mounted spring arm i yunderside of the plate 2a as shown in Figure 9.

This lamp maybe 'connected from the control circuit to ground as indicated in Figure 17.

I haveherein particularly shown and described a preferred embodiment of my invention, but it will be understood that this embodiment is subject to changes and modications within the range of engineering skill without departure from the scope of my invention, which I endeavor to express according to the following claims.

I claim:

1. In a telegraphone including a magnetizable element and reversible drive mechanism for said element: the combination of means for reversing said drive mechanism; a pair of independentlyreciprocable control devices for said reversing means; means associated with said element for operating said respective control devices in response to driven movement of the element; and means rendered effective upon completion of a reciprocation of either one of said control devices following the operation of the other, for restrictively influencing the controlling action of said devices on said reversing means whereby to prevent operation of the reversing -means twice in succession by either one of said devices.

2. `In a telegraphone including a magnetizable element and reversible drive mechanism for said element: the combination of reversing means for said drive mechanism; a control device for said reversing means associated with said element and reci-procated through one cycle at the end of travel of the element in one direction; and means controlled by said control device and operated in response only to a complete reciprocation thereof, for actuating said reversing means. I

3. In a telegraphone including a magnetizable element and a reversible drive mechanism for said element: the combination of means successively operable for reversing said drive mechanism; electrically energizable means associated with said reversing means and adapted upon the termination of each energization thereof to reverse said drive mechanism; a pair of current supply cir. cuits for said electrically energizable means; a pair of normally open switches in said supply circuits respectively, said switches being closed momentarily by said magnetic element in response to driven movement of the element in different directions and causing momentary energization of said cnergizable means to reverse said drive mechanism at the termination of said energization; and means controlled by said reversing means for valternately disabling said supply eircilits upon the opening of each of said switches.

4. .A control system for a reversible drive mechanism for the magnetic recording element of a telegraphone, comprising a pair of independently-reciprocable control devices each associated with said magnetic element, one of said devices being reciprocated in response to driven movement of said element in one direction and the other to driven movement of said element in the necting said devices into said system to render the respective devices effective to reverse said drive mechanism; and means to operate said last-mentioned -means at the completion of one reciprocation of either of said devices following a reciprocation of the other of said devices.

5. In a telegraphone including a magnetizabie element, a reversible drive mechanism for said element and means advanceable to successive positions for reversing said drive mechanism: a stepping mechanism for successively advancing said reversing means at the end of travel of the magnetic element in each direction, comprising electrical means momentarily energized at the end of travel of the element in each direction, a ratchet wheel coupled to said reversing means, a feed Ipavvl cooperating with said ratchet wheel and retracted relative thereto by said electrical means upon each energization of the latter, and means for operating said feed pawl to advance said reversing means upon a termination of energization of said electrical means.

6. In a telegraphone including a magnetizable element, a reversible drive mechanism for said element and means advanceable to successive positions for reversing said drive mechanism: the combination of a stepping mechanism for successively advancing said reversing means, said stepother direction; means for alternately con- 16 ping mechanism being electrically energizable and responsive within a predetermined time interval following the initiation of each energization thereof to advance said reversing means by one step; switch means associatedwith said magnetic element for controlling said stepping mechanism; and a plurality of successive corrugations of said magnetizable element for holding said switch means operated for a period at least as great as said time interval in response to driven movement of said element.

'1. In a telegraphone including a magnetizable element, a reversible drive mechanism for said element and means advanceable to successive positions for reversing said drive mechanism; a stepping mechanismA for successively advancing said reversing means at the end of travel of the magnetic element in each direction, comprising 'electrical means energizable to condition said stepping mechanism for operation, means for producing an actuation of said stepping mechanism at the termination of an energization of said electrical means for a predetermined time interval, switch means associated with said magnetic element for controlling said electrical means, and thickened portions on said element for holding the switch means operated for at least said time interval at the end of travel of the tape in each direction.

8. In a telegraphone having a drivable magnetic element and reversible drive means for said element: the combination of reversing means for said drive means; reciprocable means effective upon each complete reciprocation thereof for operating said reversing means, said reciprocable means comprising control means operatively associated with said magnetic element, and said magnetic element having predetermined portions movable past said control means on driven movement of the element and each effective upon being so moved to produce a complete reciprocation of said reciprocable means.

9. In a telegraphone having a drivable magnetic element and reversible drive means for said element: the combination of reversing means for said drive means; a pair of control devices for said reversing means each eiective on movement from an unoperated position to an operated position and back again to cause operation of said reversing means, said control devices being associated operatively with different portions of said magnetic element and biased to normally occupy unoperated positions, said magnetic element having predetermined portions movable past said control devices respectively. on driven movement of the magnetic element. for momentarily holding the respective control devices in operated positions to cause reversal of said drive means; and means responsive to operation of each control device for disabling the same and concurrently rendering the other effective.

l0. In a telegraphone having a movable magnetic element, means for driving said element in diierent directions, and means advanceable by steps for successively reversing said drive means: the combination of means for intermittently advancing said reversing means, including electromagnetic means energizable to put said advancing means in condition for operation and spring means for advancing said reversing means one step upon said electromagnetic means being deenergized; a current supply circuit for said electromagnetic means; and switch means in said circuit operatively associated with said magnetic element and closed momentarily upon movement of 17 said element through a predetermined portion of travel thereoi'.

11. In a telegraphone including a movable magnetic element, means for driving said element in different directions, means advanceable by steps for successively reversing said drive means, and a pair of switches operatively associated with said magnetic element lone of which is closed momentarily at the end of travel of said element in one direction and the other of which is closed momentarily at the end of travel of said element in the other direction: the combination of a ratchet 'wheel coupled to said reversing means, a feed pawl for said ratchet wheel, an electromagnetic means for retracting said pawl for subsequent operation, a spring for advancing said pawl when 18 means serially including said switches respectively, and means responsive to each advance of said reversing means for disabling one of said i supply circuits and conditioning the other for l operation.l

RICHARD M. soMERs.

REFERENCES CITED The following references are of record in the 1 fue of thispatent:

UNITED STATES PATENTS 

